| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.felix.resolver.util; |
| |
| import java.lang.reflect.Array; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| public class CopyOnWriteSet<E> implements Set<E>, Cloneable { |
| |
| Object[] data; |
| |
| public CopyOnWriteSet() { |
| data = new Object[0]; |
| } |
| |
| public CopyOnWriteSet(CopyOnWriteSet<? extends E> col) { |
| data = col.data; |
| } |
| |
| public CopyOnWriteSet(Collection<? extends E> col) { |
| data = col.toArray(new Object[col.size()]); |
| } |
| |
| public Iterator<E> iterator() { |
| return new Iterator<E>() { |
| int idx = 0; |
| public boolean hasNext() { |
| return idx < data.length; |
| } |
| @SuppressWarnings("unchecked") |
| public E next() { |
| return (E) data[idx++]; |
| } |
| public void remove() { |
| CopyOnWriteSet.this.remove(--idx); |
| } |
| }; |
| } |
| |
| public int size() { |
| return data.length; |
| } |
| |
| public boolean add(E e) { |
| Object[] d = data; |
| if (d.length == 0) { |
| data = new Object[] {e}; |
| } else { |
| for (Object o : d) { |
| if (o == null ? e == null : o.equals(e)) { |
| return false; |
| } |
| } |
| Object[] a = new Object[d.length + 1]; |
| System.arraycopy(d, 0, a, 0, d.length); |
| a[d.length] = e; |
| data = a; |
| } |
| return true; |
| } |
| |
| private void remove(int index) { |
| Object[] d = data; |
| int len = d.length; |
| Object[] a = new Object[len - 1]; |
| int numMoved = len - index - 1; |
| if (index > 0) { |
| System.arraycopy(d, 0, a, 0, index); |
| } |
| if (numMoved > 0) { |
| System.arraycopy(d, index + 1, a, index, numMoved); |
| } |
| data = a; |
| } |
| |
| public Object[] toArray() { |
| return data.clone(); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public <T> T[] toArray(T[] a) { |
| int size = data.length; |
| if (a.length < size) |
| // Make a new array of a's runtime type, but my contents: |
| return (T[]) copyOf(data, size, a.getClass()); |
| System.arraycopy(data, 0, a, 0, size); |
| if (a.length > size) |
| a[size] = null; |
| return a; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof CopyOnWriteSet)) { |
| return false; |
| } |
| Object[] o1 = data; |
| @SuppressWarnings("rawtypes") |
| Object[] o2 = ((CopyOnWriteSet) o).data; |
| if (o1 == o2) { |
| return true; |
| } |
| int l = o1.length; |
| if (l != o2.length) { |
| return false; |
| } |
| loop: |
| for (int i = l; i-- > 0;) { |
| Object v1 = o1[i]; |
| for (int j = l; j-- > 0;) { |
| Object v2 = o2[j]; |
| if (v1 == v2) |
| continue loop; |
| if (v1 != null && v1.equals(v2)) |
| continue loop; |
| } |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Arrays.hashCode(data); |
| } |
| |
| /** |
| * Clone this object |
| * |
| * @return a cloned object. |
| */ |
| @Override |
| @SuppressWarnings("unchecked") |
| public CopyOnWriteSet<E> clone() { |
| try { |
| return (CopyOnWriteSet<E>) super.clone(); |
| } catch (CloneNotSupportedException exc) { |
| InternalError e = new InternalError(); |
| e.initCause(exc); |
| throw e; //should never happen since we are cloneable |
| } |
| } |
| |
| public boolean isEmpty() { |
| return size() == 0; |
| } |
| |
| public boolean contains(Object o) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public boolean remove(Object o) { |
| int index; |
| if ((index = indexOf(o, data, data.length)) >= 0) { |
| remove(index); |
| return true; |
| } |
| return false; |
| } |
| |
| private static int indexOf(Object o, Object[] d, int len) { |
| if (o == null) { |
| for (int i = len; i-- > 0;) { |
| if (d[i] == null) |
| return i; |
| } |
| } else { |
| for (int i = len; i-- > 0;) { |
| if (o.equals(d[i])) |
| return i; |
| } |
| } |
| return -1; |
| } |
| |
| public boolean containsAll(Collection<?> c) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public boolean addAll(Collection<? extends E> c) { |
| Object[] cs = c.toArray(); |
| if (cs.length == 0) |
| return false; |
| Object[] elements = data; |
| int len = elements.length; |
| int added = 0; |
| // uniquify and compact elements in cs |
| for (int i = 0; i < cs.length; ++i) { |
| Object e = cs[i]; |
| if (indexOf(e, elements, len) < 0 && |
| indexOf(e, cs, added) < 0) |
| cs[added++] = e; |
| } |
| if (added > 0) { |
| Object[] newElements = copyOf(elements, len + added); |
| System.arraycopy(cs, 0, newElements, len, added); |
| data = newElements; |
| return true; |
| } |
| return false; |
| } |
| |
| public boolean retainAll(Collection<?> c) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public boolean removeAll(Collection<?> c) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public void clear() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public static <T> T[] copyOf(T[] original, int newLength) { |
| return (T[]) copyOf(original, newLength, original.getClass()); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public static <T,U> T[] copyOf(U[] original, int newLength, Class<? extends T[]> newType) { |
| T[] copy; |
| if ((Object) newType == Object[].class) { |
| copy = (T[]) new Object[newLength]; |
| } else { |
| copy = (T[]) Array.newInstance(newType.getComponentType(), newLength); |
| } |
| System.arraycopy(original, 0, copy, 0, Math.min(original.length, newLength)); |
| return copy; |
| } |
| } |